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Using an approach of combining Fourier transform infrared spectroscopy with resonant illumination from a secondary external light source, we have measured the photocurrent (PC) for multiple layers of self-assembled InAs dots embedded in a matrix of InP. Without external illumination, we observe photoexcitation of electrons from bound states in the dots to the InP barrier. By additional illuminatio
Quantum metrology is a rapidly growing field of quantum information science that aims to exploit the counter-intuitive properties of quantum systems to estimate physical quantities with better-than-classical precision. The field primarily deals with the problem of estimating system parameters, which may or may not directly be associated to an observable. A prominent result of quantum metrology is
Entanglement production is one of the properties of interest when studying nanoscale systems. Not only does entanglement between subsystems hints at other non-classical behaviour and effects that may be of interest to applications; the resource of entangled systems themselves is one on which many future devices and protocols may depend on. In this thesis work, a system of two quantum dots coupled
Nanowire quantum dots have shown promise as energy filters in thermoelectric applications. However, anomalous effects in the thermocurrent have been observed when heat is applied in close proximity to the quantum dot. This work began as an experimental investigation but transitioned to a data analysis project due to hardware failure. Using previously acquired experimental data, we compare the meas
The complex interplay by tunneling and scattering in quantum cascade lasers is analyzed with nonequilibrium Green's functions. Data for a recently proposed simple structure based on only two wells per period is presented. This simple structure allows to visualize the relevance of the tunneling resonance very clearly. It is argued that a QCL design needs at least three levels per period, thus furth
Sorption balances are instruments in which samples are weighed as they are exposed to a programmed relative humidity (RH). Such instruments are used to measure sorption isotherms and to study solid-vapour interaction. There are different methods to validate the performance of the RH generation in such instruments by charging them with saturated salt solutions and ramping/stepping the RH past the d
We demonstrate that we can use the extreme ultraviolet radiation produced by high order harmonic generation to perform photoionization experiments. With harmonics from the 11th to the 69th of a 140 fs Cr:LiSAF laser operating at 825 nm, we measure the relative photoionization cross sections of xenon, krypton, argon and neon over the range 10 to 110 eV. With narrow bandwidth harmonics produced by a
2016December 15 Richard Shearmur, School of Urban Planning, McGill University. Title: Geographies of innovations: confusions, perplexities, and ways forwardMay 9 Rikard Eriksson, Department of Geography and Economic History, Umeå University. Title: Co-worker networks, agglomeration and regional development 2015November 23 Cecilia Tacoli, Human Settlements Group, International Institute for Environ
https://www.keg.lu.se/invited-speakers-human-geography - 2026-07-13
A simulation scheme based on nonequilibrium Green's functions for biased periodic semiconductor heterostructure devices is presented in detail. The implementation can determine current and optical gain both for small and large optical fields. Specific results for superlattices, quantum cascade lasers, and quantum cascade detectors are shown which demonstrate the capabilities of the approach.
Semiconductor nanostructure based devices provide new opportunities for contributing to a sustainable energy usage. This includes harvesting of energy (solar cells) and saving of energy, e.g. in lighting (light-emitting diodes, LEDs) and transfer of energy (power devices). However, development and improvement of nanostructure devices requires thorough characterization and understanding on a singleSemiconductor nanostructure based devices provide new opportunities for contributing to a sustainable energy usage. This includes harvesting of energy (solar cells) and saving of energy, e.g. in lighting (light-emitting diodes, LEDs) and transfer of energy (power devices). However, development and improvement of nanostructure devices requires thorough characterization and understanding on a single
